The invention relates to an illuminating device for a microscope with an illumination magazine comprising a plurality of light emitting units. A mechanical illuminator changer can change the light emitting unit currently active in the operative position. A filter magazine having a plurality of filter units is present, wherein a mechanical filter changer for changing the filter unit currently in the active operative position is associated with the filter magazine. At least one mechanical coupling component is provided for cooperation with the filter changer and the illuminator and for uniquely assigning each filter unit to a specific light emitting unit.